[PATCH] fuse: validate rootmode mount option

If rootmode isn't valid, we hit the BUG() in fuse_init_inode.  Now
EINVAL is returned.

Signed-off-by: Timo Savola <tsavola@movial.fi>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index b98b20d..68ae87c 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -552,3 +552,8 @@
  * Remove connection from control filesystem
  */
 void fuse_ctl_remove_conn(struct fuse_conn *fc);
+
+/**
+ * Is file type valid?
+ */
+int fuse_valid_type(int m);